Molded indurated fiber article and process for making the same



Aug. 10 1926. 1,595,856

H.H.CLARK MOLDED INDURATED FIBER ARTICLE AND PROCESS FOR MAKING THE SAME Filed June 1, 1925 [NV NTOR fly? if/a/v ATTORNEY Patented Aug. 10, 1926.

UNITED STATES PATENT OFFICE.

HORACE. H. CLARK, OF FARMINGDALE, NEW JERSEY, ASSIGNOR TO CLARK FIBRE PRODUCTS CORPORATION, A CORPORATION OF DELAWARE.

MOLDED INDURATED FIBER ARTICLE AND PROCESS FOR MAKING THE SAME.

Application filed June 1, 1925. Serial No. 34,068.

My present invention relates generally to the manufacture of what is known as indurated fiber, and comprises certain improvements in the process of such manufacture which result in a product having marked advantages for use in. any subsequent molding operation which requires the material to be sharply bent through a considerable angle, or to be considerably expanded. Ordinarily indurated fiber products are apt to break at the point of fiexure when bent sharply in molding operations, and to split when expanded to any considerable degree in such molding operation, therey causing a waste of raw material and basic labor, but I have discovered that these undesirable results can be avoided wholly, or to a great degree, by certain simple modifications in existing processes of manufacturing the tubes and sheets of the indurated fiber which are used as raw materials in the subsequent molding processes.

My invention applies to those processes in which the indurated fiber product is made by saturating or impregnating sheets of paper formed of cellulose fiber with a suitable solution (usually of an acid character) and then superposing the proper number of such sheets one upon another, pressing the same together, allowing the composite mass to dry or cure under proper conditions, and washing out any excess of the solution. In many cases the proper number of the treated sheets are wound on a mandrel to build up a tube of the desired thickness of wall and these tubes, or sections of them, are subsequently used in molding tubular objects such as goggle frames, bushings having electrically insulating properties, and so forth, but if the wall of any suph tube section is bent back upon itself in such molding operation, or one end of the section is expanded to a considerably larger diameter to produce a tapered shape, the ordinary fiber tube is apt to split or break.

It is well known that in practically all kinds of paper a greater number of the constituent fibers are apt to be arranged in the general direction of one superficial dimension of the sheet than in the general direction of the other dimension, and that is especially true' of machine made paper, such as the wood pulp or the cottonliber paper used in making indurated fiber, because the fiber in such paper stock is largely drawn'out on the wire belt in the direction of travel of the belt in the paper making process. That is to say, while the fibers in the completed sheet of paper run in all directions, as is necessary to produce the felting action which holds them together to form the sheet, a majority of such fibers will extend in directions inclined at angles of less than degrees to the longer dimension-of such paper web. This makes the web of paper delivered by the paper mill much stronger in a direction lengthwise of said web, than crosswise thereof.

I have discovered that when a number of such treatedsheets of paper are compacted together to form a sheet of indurated fiber, or one or more such sheets are wound on a mandrel to form a tube of indurated fiber by the usual process above described, such sheet or tube wall also has a much greater flexibility (meaning capacity for bending without rupture) when bent in planesin which this grain of the paper extends, than when bent in a direction at right angles thereto.

To utilize this discovery when material of this kind is employed in making articles having an edge which is to be bent in the molding, as in the case of short lengths of tubing which have their edges bent back inwardly to form a double thickness and a rounded surface at the edge, or in the case of annular bands which are doubled over on themselves to form a ring of U-shaped cross section to be cemented over the edge of a tubular article to reinforce the edge thereof, the most perfect results are secured by the following procedure:

The original sheets of paper should be wound on the mandrel in such manner that the fiber of the paper will run lengthwise of the mandrel and lengthwise of the tube formed thereon. Ordinarily the paper is obtained in long strips or webs rolled up as it comes from the paper making machine, and as above explained, the fibers forming the paper have been arranged by the process of manufacture in such positions that a majority of them extend approximately lengthwise of this strip, thus forming a grain" in the paper. Consequently, to secure the above stated result the sheets or sections cut from this original roll or long strip of paper should be fed sidewise through the bath and to the mandrel. When this is done any short tubes or rings formed by cutting the original tube into short sections can have their edges bent back sharply in heated dies to form the desired edge reinforcing and smoothing finish without danger of rupture, such as might occur when the fiber runs circumferentially of the tube sections and this. bending is done, as would be the case if the paper sheets other way,-that is, in a direction parallel to the length of the original strip. This is particularly important in the manufacture of goggle frames out of this type of material, in which goggle frames the inner edge of each tube holding a lens is bent inward and backward through 180 degrees to form a smooth rim that bears against the wearers face.

Also, in making these goggle frames, or other tubular articles, of flaring, or frustoconical shape, it is usually necessary to produce such shape by expanding in'a die an originally cylindrical section of the material of a lesser diameter. In the formation of the original tube from which such cylindrical section is to be cut, such tube shrinks considerably in the drying or curing steps of the process, and it is important, whenever possible, to make the original tube, as wound on the mandrel, of approximately the diameter of the flared portion of the completed article, and to so carry out the rest of the process that the tube will have shrunk, when finished, to approximately the diameter of the smallest part of the completed article. When these precautions have been observed the tube sections, or any portion thereof, can be expanded in heated dies to the original diameter without danger of rupture.

Thus, in the case of the goggle frames which hold lenses of 1% inches diameter and flare out to an internal diameter of 2 A inches at the innner edge which bears against the wearers face, the mandrel on which the original tubes are wound should have a diameter of 2 ,4; inches, and the original tubes formed thereon should be shrunk, in manufacture, to an-internal diameter of 1% inches.

,lVhen these directions are followed goggle frames of the standard sizeand shape above had been fed to the mandrel the 1,5e5,ese

described can be rapidly molded out of this type of material with practically no waste from breakage in the molding operation, or from any other defects arising from partial rupture of the material in the process of manufacture.

The above described process of making tubular articles of indurated fiber according to my invention is illustrated roughly in the accompanying sheet of drawings in which,

Fig. 1 is a diagram of the tube making process, the apparatus being shown inperspective.

Fig. 2 is a perspective view of a tube of fiber when stripped from the mandrel.

Fig. 3 is a similar view of the same after being cured and shrunk, and

Fig. 4 is a section of a goggle frame made therefrom.

Throughout the drawings like reference characters indicate like parts.

1 is a web of machine-made paper being unrolled from roll 2. Thisis transversely cut as at 3 to form a sheet 4, which at first rests on table 11 and is then passed through the proper bath in pan 5 (as indicated at t) and wound upon mandrel 6 (as indicated at 4") under regulated pressure from any suitable device 7 which will act as a squeegee to remove any undesired excess. of the impregnating liquid absorbed from the bath in pan 5. After the tube of fiber 8 so formed has been pulled off mandrel 6, and aired and dried it shrinks to lesser size 8?, according to the amount of liquid allowed to remain in it when taken from mandrel 6, the character-of said liquid, etc.

The main point of the present invention is that the sheets 4, P, 4", should be fed sidewise to mandrel 6, so that the majority of the fibers composing it will extend more nearly parallel to the axis of the tube 8 so formed, than to the circumference thereof. This general direction of fiber is indicated by -F in the drawings. The result of this is that said fiber also runs lengthwise of any tubular article formed from a section of the cured tube 8*, such as the goggle frame, shown in Fig. 4, and if an edge of such tubular section has to be bent back onitself, as shown at 10, my improved material will undergo such bending without rupture, while ordinary indurated fiber will break.

If the indurated fiber body is formed in sheets or blocks, (instead 'of in tubes) by any suitable process as by splitting and flattening out tubes 8 or 8 for use in any predetermined molding process, the same care should be observed to have the sheets of paper so assembled that the grain of all will run in the same direction, and thi direction, in the completed article, be in ines running around any bends therein, rather than parallel to the axis of suchbend.

The second point here illustrated is that making mandrel 6 of the diameter desired for the larger end 10 of the goggle frame, and so regulating the bath in pan 5, and other treatment of the materials that when tube 8 has been cured it will have shrunk to the size shown in Fig. 3 which has the diameter of the smaller end of goggle frame 9. The result is that when a short section of tube 8 is expanded, in molding to form the goggle frame 9, it will never be stretched beyond its original diameter shown in 8, and the fibers will not be pulled apart or otherwise forced from their original arrangements, and no rupture will result.

As a general but concise restatement of certain features of my invention I may say that the fibers should be so arranged in the blank, of whatever shape, that after any portion of its wall is subsequently bent in a predetermined direction a majority of the fibers at and around such bend will lie in lines widely divergent from parallelism with the line along, or around, or about which said wall has been bent. In working up tubular blanks made in accordance with one particular embodiment of my invention hereinbefore described, the bent wall portions, flanges or turned over edge portions of such tubular blanks may be considered as each composed of a connected series of infinitely small sections each of which is bent about or along a short straight line constituting an element of the circle forming the inner or outer circumference of the tube, according to whether the bend is inward or outward of the tube. In the case of such tubular bodies or blanks in which the majority of fibers were substantially parallel to the axis of the original tube, each wall portion when bent must be flexed along a line,

widely divergent from parallelism with said axis to embody my invention, i. e. so as to I cause the majority of the fibers at each bent portion to extend in directions around the curvature of the bend, thereby having served practically as hinges at the moment of bend- Having described my invention, I claim: 1.. The herein described process of forming bent molded articles out of a body of indurated fiber which comprises so assembling the sheets of paper employed as raw matethat a majority of extend in a directo the plane in the fibers therein will each tion more nearly parallel which said fiber will move when said body, of which it is a component, is bent, than to a line along which said body is bent.

2. The herein described process of forming tubular molded articles of indurated fiber having a backwardly turned edge at an end of such completed tubular article, which process comprises forming the original tube by winding on a mandrel a sheet of paper the majority of the fibers in which extend approximately parallel to the axis of said mandrel, whereby when the wall of the tube so formed is bent backwards on itself at an end thereof the liability to fracture at the point of bending in the molding operation is reduced.

3. The herein described process of forming, out of indurated fiber, tubular molded articles of non-uniform diameter which coinprises winding atreated sheet of fiber on a mandrel of a diameter approximating the largest diameter of the completed article andthen shrinking saidtube throughout its entire length in the subsequent steps of the process to a diameter approximately equal to the smallest diameter of the completed article.

4:. As a new article of manufacture, a tubular body of indurated fiber having portions of its walls bent sharply along lines widely divergent from parallelism with the axis of said tubular body and a majority of the fibers at each said bent portion extending in directions around the curvature of its bend.

5. As a new article of manufacture a tubular body of indurated fiber having an edge turned back upon itself in which a majority of the fibers are arranged in planes approximately parallel to the axis of said tubular body.

6. A product of the herein described process, being a molded mass of indurated fiber having portions sharply bent through angles of at least 90 degrees and with a majority of the fibers at, each said bent portion lying in lines widely divergent from parallelism with the line along which said portion is bent.

7 As a new article of manufacture, a tubular article made of indurated fiber, which article hasa wall portion bent in a direction substantially radial of the tube, a majority of the fibers at said bent portion being so arranged as to extend in lines inclined at angles of more than 45 degrees to the line.

which it is wound to form the desired tube,

whereby the majority of the fibers of the original web, which fibers extended approximately longitudinally thereof as a normal result of the paper making process, will be in a direction sidewise of the disposed in the completed tubes along lines approximately parallel to the axes of said tubes;

9. The herein described process of forming, out of indurated fiber, tubular, molded articles of non-uniform diameter which process comprises Winding on a mandrel ofa diameter approximating the largest diameter'of the completed article, a partly dried sheet of material of a character adapted to contract superficially on further drying, and then permitting the tube so formed to shrink by its own contraction in further drying dur- 10 ing subsequent steps of the process to a diameter approximately equal to the smallest diameter of the completed article.

. HORACE H. CLARK. 

